Spent Mushroom Compost

Hi all,

I am currently trying to fill eight new raised beds (4'x12').  I was hoping to use manure but the stuff delivered to the plots this year is useless (all straw and no manure and the smell off it makes me think that they were possibly waiting at the back end of the horse to collect the bit of manure that is in it!!!!!).

I have been offered 5 builders sacks (1 m3 each) full of spent mushroom compost more or less for the cost of delivery and I was just wondering if anyone has any experience of using this.  I was hoping to add it to the beds and leave it for a month or two and then rotavate it into the soil as I need the beds but not sure if it is any good or not.

E

Hi

I used spent mushroom compost to start off my raised beds together with some not great topsoil, random compost (old grow bags, used compost from last year's pots etc while waiting for compost heap on plot to get going) and a bit of well rotted manure because there was a bit going spare. The spent mushroom compost worked for me - the worms love it.   There's some talk that it makes the soil alkaline - but there was an article in one of the weekend papers from a garden journalist saying that it doesn't and she uses it every year. Unfortunately can't find it to link to it.

I think you do have to mix it with something though - just manure or just SMC would probably be a bit of a shock to young plants - I stand to be corrected by anyone else coming along though.

I've used it two years on the trot and will be ordering more this spring. The other advantages are it's relatively lights to handle and move, not smelly and you get bonus mushrooms popping up!

We tend to avoid mushroom composts since they're fairly alkaline, so do know your soil pH before adding masses to it.